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What are two symptoms that DNS is an issue when developing and testing network scripts? (Choose two.)

• 1XX status code
• 403 error code
• authentication failure
• host IP address showing 169.x.x.x
• no connection between the app and a remote server

When dealing with DNS issues in the context of developing and testing network scripts, the two correct symptoms are:

1. Authentication failure
2. No connection between the app and a remote server

Here’s a detailed explanation of each option:

1. Authentication Failure

Explanation:

• While authentication failures are not typically associated directly with DNS issues, they can occur if the DNS server cannot resolve the domain name of the authentication server.
• This can prevent the system from reaching the server to validate credentials, leading to authentication failures.

Detailed Symptoms:

• The application or script may repeatedly prompt for credentials or fail to authenticate even with correct credentials.
• This could be due to the inability to resolve the domain name of the authentication server, preventing the connection required for the authentication process.
• Network troubleshooting tools like ping or nslookup might show that the domain name cannot be resolved, indicating a DNS resolution issue.

2. No Connection Between the App and a Remote Server

Explanation:

• DNS is essential for translating domain names into IP addresses. If DNS fails, the app cannot resolve the remote server’s domain name, leading to connection failures.
• Without a valid IP address from the DNS server, the application cannot establish a connection to the remote server.

Detailed Symptoms:

• The app or network script may report errors related to the inability to reach the server, such as timeouts or host not found errors.
• Tools like ping or traceroute might fail to resolve the remote server’s domain name, confirming a DNS issue.
• This can halt the functionality of network scripts that rely on remote servers, making it impossible to test or run the scripts effectively.

Why the Other Options Are Less Relevant to DNS Issues:

• 1XX status code: These are HTTP informational responses that indicate the request was received and is continuing to be processed. They do not indicate DNS issues.
• 403 error code: This indicates a permission issue, where the server refuses to authorize the request. It is related to access control rather than DNS resolution.
• Host IP address showing 169.x.x.x: This is typically a symptom of DHCP issues rather than DNS issues. It indicates that the system could not obtain a valid IP address from the DHCP server and instead self-assigned an APIPA address.

In summary, authentication failure and no connection between the app and a remote server are the two correct symptoms of DNS issues when developing and testing network scripts.